首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2893篇
  免费   152篇
  国内免费   12篇
耳鼻咽喉   19篇
儿科学   65篇
妇产科学   48篇
基础医学   402篇
口腔科学   81篇
临床医学   198篇
内科学   721篇
皮肤病学   48篇
神经病学   204篇
特种医学   96篇
外科学   356篇
综合类   5篇
一般理论   1篇
预防医学   135篇
眼科学   63篇
药学   313篇
中国医学   2篇
肿瘤学   300篇
  2023年   18篇
  2022年   39篇
  2021年   72篇
  2020年   41篇
  2019年   47篇
  2018年   57篇
  2017年   34篇
  2016年   37篇
  2015年   76篇
  2014年   70篇
  2013年   98篇
  2012年   185篇
  2011年   173篇
  2010年   95篇
  2009年   84篇
  2008年   167篇
  2007年   198篇
  2006年   194篇
  2005年   172篇
  2004年   153篇
  2003年   170篇
  2002年   144篇
  2001年   62篇
  2000年   51篇
  1999年   55篇
  1998年   44篇
  1997年   33篇
  1996年   27篇
  1995年   30篇
  1994年   26篇
  1993年   24篇
  1992年   43篇
  1991年   38篇
  1990年   29篇
  1989年   40篇
  1988年   25篇
  1987年   26篇
  1986年   24篇
  1985年   16篇
  1984年   12篇
  1983年   15篇
  1981年   14篇
  1980年   7篇
  1979年   7篇
  1977年   11篇
  1976年   9篇
  1974年   11篇
  1973年   7篇
  1971年   6篇
  1968年   6篇
排序方式: 共有3057条查询结果,搜索用时 296 毫秒
101.
102.
Naunyn-Schmiedeberg's Archives of Pharmacology - Abnormal G protein-coupled receptor kinase 2 (GRK2) accumulation has a crucial role in the development of insulin resistance and diabetes....  相似文献   
103.
104.
Graefe's Archive for Clinical and Experimental Ophthalmology - To determine the relationship between the peripapillary choroidal thickness (ppCT) and the degree and distribution of the...  相似文献   
105.
106.
107.
The purpose of this study was to evaluate the mechanism of action and the inhibiting effects of two types of desensitizers against dentin demineralization using pre-demineralized hypersensitivity tooth model in vitro. In this study, we confirmed that a hypersensitivity tooth model from our preliminary experiment could be prepared by immersing dentin discs in an acetic acid-based solution with pH 5.0 for three days. Dentin discs with three days of demineralization were prepared and applied by one of the desensitizers containing calcium fluoro-alumino-silicate glass (Nanoseal, NS) or fluoro-zinc-silicate glass (Caredyne Shield, CS), followed by an additional three days of demineralization. Dentin discs for three days of demineralization (de3) and six days of demineralization (de6) without the desensitizers were also prepared. The dentin discs after the experimental protocol were scanned using swept-source optical coherence tomography (SS-OCT) to image the cross-sectional (2D) view of the samples and evaluate the SS-OCT signal. The signal intensity profiles of SS-OCT from the region of interest of 300, 500, and 700 µm in depth were obtained to calculate the integrated signal intensity and signal attenuation coefficient. The morphological differences and remaining chemical elements of the dentin discs were also analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. SS-OCT images of CS and NS groups showed no obvious differences between the groups. However, SS-OCT signal profiles for both the CS and NS groups showed smaller attenuation coefficients and larger integrated signal intensities than those of the de6 group. Reactional deposits of the desensitizers even after the additional three days of demineralization were observed on the dentin surface in NS group, whereas remnants containing Zn were detected within the dentinal tubules in CS group. Consequently, both CS and NS groups showed inhibition effects against the additional three days of demineralization in this study. Our findings demonstrate that SS-OCT signal analysis can be used to monitor the dentin demineralization and inhibition effects of desensitizers against dentin demineralization in vitro.  相似文献   
108.
Aims/IntroductionSodium–glucose cotransporter 2 inhibitors (SGLT2i) are used worldwide because of their multiple benefits for patients with type 2 diabetes. The purpose of this study was to determine the efficacy and safety of SGLT2i in patients with type 1 diabetes.Materials and MethodsPatients with type 1 diabetes who had been treated with SGLT2i for >12 weeks were included in this retrospective observation study. We recorded the changes in body mass, insulin dose, blood and urine test data, and adverse events. The changes in day‐to‐day glucose variability, as the primary end‐point, was evaluated using the interquartile range (P25/P75) of the ambulatory glucose data obtained using continuous glucose monitoring.ResultsA total of 51 patients (37 women; mean age 52.7 years) were included. Glycated hemoglobin and body mass significantly decreased by 0.4% and 1.6 kg, respectively. The total required insulin dose decreased by 9.4% (42.7 ± 26.6–38.7 ± 24.3 units/day). Continuous glucose monitoring data were obtained from 30 patients. P25/P75 decreased by 17.6 ± 20.7% during SGLT2i treatment (P < 0.001). The percentage of time per day within the target glucose range of 70–180 mg/dL significantly increased (from 42.2 to 55.5%, P < 0.001), without an increase in the percentage of time spent in the hypoglycemic range (<70 mg/dL). Urinary ketone bodies were detected in four patients (7.8%), but none developed ketoacidosis.ConclusionsSGLT2i improved day‐to‐day glucose variability and time in the target glucose range, without increasing frequency of hypoglycemia, in patients with type 1 diabetes, and reduced glycated hemoglobin, body mass and the required insulin dose.  相似文献   
109.
Several dental materials contain silver for antibacterial effect, however the effect is relatively low. The reason for the lower antibacterial efficacy of silver is considered to be the fact that silver ions bind to chloride ions in saliva. To develop new effective silver antibacterial agents that can be useful in the mouth, we synthesized two novel amino acid (methionine or histidine)–silver complexes (Met or His–Ag) loaded with montmorillonite (Mont) and analyzed their antibacterial efficacy. At first the complexes were characterized using nuclear magnetic resonance (NMR), and amino acid–Ag complex-loaded Mont (amino acid–Ag–Mont) were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The antibacterial efficacy of these materials in dental acrylic resin was then investigated by bacterial growth measurement using a spectrophotometer. As controls, commercially available silver-loaded zeolite and silver-zirconium phosphate were also tested. Dental acrylic resin incorporating His–Ag–Mont strongly inhibited Streptococcus mutans growth. This was explained by the fact that His-Ag complex revealed the highest amounts of silver ions in the presence of chloride. The structure of the amino acid–Ag complexes affected the silver ion presence in chloride and the antibacterial efficacy. His–Ag–Mont might be used as antibacterial agents for dental materials.  相似文献   
110.
The cardiovascular effects of SIPI-549 [4'-methyl-7-(2-hydroxy-3-isopropylaminoproxy)-flavone hydrochloride] were investigated in isolated canine atrial and ventricular muscles perfused with heparinized arterial blood from a donor dog. When SIPI-549 was administered intravenously to the intact donor dog, a slight hypotension was induced in a dose range of 0.01 to 3 mumol/kg. At the same time, slight negative chronotropic and inotropic responses appeared in isolated and perfused atria, suggesting a cardiac depressant action. Direct administration of SIPI-549 into the cannulated sinus node artery of the isolated atrium produced negative inotropic and biphasic chronotropic responses in a dose related manner (0.01-1 mumol). SIPI-549 also induced a dose-dependent decrease in developed tension of the isolated left ventricle. The SIPI-549-induced negative chronotropic and inotropic effects were not modified by atropine in doses which blocked carbachol-induced negative chronotropic and inotropic effects. The SIPI-549-induced positive chronotropic effects were inhibited by propranolol but significantly potentiated by imipramine treatment, indicating that a large dose of SIPI-549 produces a release of catecholamine via a non-tyramine like action. Large doses of SIPI-549 did not significantly affect norepinephrine-induced positive chronotropic effects. These results indicate that SIPI-549 may have non-cholinergic cardiac depressant properties and no beta-adrenoceptor blocking activity. However, it appears to elicit a release of catecholamines in a non-tyramine-like manner at relatively large doses.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号